Are critters also sailing through the Northwest Passage?

melting sea iceIt’s hard to ignore the melting sea ice these days. Images of starving polar bears are everywhere, each one eliciting a slow, sad head shake. In satellite images taken since 1979, you can see the arctic sea ice coverage in the summer diminishing by about 34,000 square miles each year (that’s an area of ice the size of Maine we are losing each year).

I have conflicted feelings towards this growing ice-free passage to the north. The sea ice loss is undoubtedly sad for the polar bears (and many other creatures that rely on the ice pack for their food or home), and is a discouraging indicator of our painful impact on the delicate balance of this planet. But it is also the only reason we are able to go on this adventure. The Northwest Passage is there because the ice is not.

How is this new waterway affecting the lives of critters that were previously turned back by the ice? Most marine mammals can’t survive in areas with thick sea ice, as they need access to the surface to breathe. Likewise, many seabirds rely on open sea for the food source. With the passage opening more and more, will these critters find new feeding grounds? New mates? New homes?

Unexpected migrations are already being observed. Pacific gray whales, which have been absent from the Atlantic for at least 200 years, showed up off the coast of Israel in 2010 and again near Namibia in Southern Africa in 2013. Shearwaters, sea birds related to the albatross, were previously only found in the northern Atlantic but have recently been spotted on the Pacific coast, as far south as California.

orcas in arcticKiller whales are one of the most widely distributed marine mammals already, but they hadn’t been seen in the arctic until recent years when pods of killer whales were spotted preying on bowhead whales, narwhals and seals. Red Robins were spotted in Tuktoyaktuk, a village in the high arctic along the opening Northwest Passage. There are Bowhead whale populations on either side of the passage, but in 2010, two tagged whales- one from the east and one from the west – were recorded feeding near each other in the arctic for 10 days before returning to their respective oceans.

As shipping increases across the arctic, small critters that wouldn’t have the capacity to make the trip on their own, like crustaceans and plankton, will find themselves on the opposite side of the continent and do their best to survive in the new environment.

Nobody really knows what these new migrations will mean for that species or for the ecosystem as a whole. In some cases, perhaps it will increase the gene pool without significant disruption to the food chain. In other cases, it is likely new introductions will bring new diseases or new predators to an already fragile environment.

As we make our way north and then east, we will be on the lookout for species that are out of place. The more knowledge we humans have about how these critters are moving and eating and surviving, the more we can do to help support and conserve their ecosystems.



Pacific species migrating through warmer Northwest Passage